Cell phone location information has a number of benefits: we can use our phones to find directions or to locate the nearest gas station, and ambulances can find us in case of an emergency. But, the fact that most of us carry around a device that can be used to track our movements at all times also calls for caution.
Recently, the ACLU has been working to make sure that, if police want to use cell-phone tracking information for a criminal investigation, they first need to obtain a warrant and show probable cause. Here in Maine, and in other states, we have sought out ways to share our legal views on this issue with the federal judges, prosecutors, and defenders.
Judge Stephen Smith, of the U.S. District Court for the Southern District of Texas, clearly took that material to heart. Judge Smith issued an order laying out in great detail the constitutional protections available to cell phone users, and holding that the Fourth Amendment requires a warrant based on probable cause if the government wants historical cell-phone location information. Catherine Crump discusses the order in greater detail on the ACLU Blog of Rights.
Here in Maine, we are going to continue to push our courts to adopt similarly protective standards.